Jerry,
This lesson applies to the world-wide-web in general not just to the Lugerforum pages.
Anytime you need information about a photo that you see on any web page, just place the mouse cursor over the image and right-click and you will be offered a menu of options. You can save the photo if you wish to your computer as I frequently do...
Another of the options is the "properties" choice.
If you select "properties" you will be shown a popup window that describes the physical properties of the photo including the URL or location... you can highlight, copy and paste this URL for use in your posts...
One in the edit mode for posting on the forum, if you click on the "Image" tag or button below the edit window, and you can paste the URL into the provided window entry and when you say OK, and post your message, the image should appear in your posting... Ed Tinker has posted a photo tutorial in the Site Feedback and Help forum that should answer many of your photo related questions. If you don't get it right on your first try, you can edit your own posts by using the pencil and paper icon that is located in each message space.
Hope this was helpful.